1. Field of the Invention
The present invention relates to a connector for connecting electric wiring, and particularly relates to an improvement of a connector with a double locking mechanism in which terminals inserted into terminal accommodating chambers of a connector housing are locked doubly so as not to be detached therefrom by a locking means provided in the connector housing and a locking pin inserted into the housing.
2. Related Art
Conventionally, the connection of a pair of electric wirings is performed by fitting, to each other, a pair of male and female terminals attached to the ends of the electric wirings respectively. It is however extremely difficult to connect many wirings pair by pair by use of terminals.
Such a connector has been used, therefore, in which a female connector housing storing a number of male terminals and a male connector housing storing a number of female terminals are fitted to each other to thereby connect a number of wirings at a time.
In such a connector, if terminals are not attached in proper positions in terminal accommodating chambers of male and female connecter housings respectively, wirings cannot be connected accurately when the connector housings are fitted to each other.
In a general connector housing, however, a worker cannot visually determine from the outside whether terminals are attached in their proper positions in terminal accommodating chambers of a connector housing.
Of the different types of connectors, there is a connector with a double locking mechanism in which terminals inserted into terminal accommodating chambers of a connector housing are locked doubly so as not to be detached from the terminal accommodating chambers by a locking means provided in the connector housing and a locking pin inserted into the housing, as disclosed in Japanese Examined Patent Publication No. Hei-4-49229.
The connector with a double locking mechanism disclosed in Japanese Patent Post-Examination Publication No. Hei-4-49229 will be described, by way of example, with reference to FIGS. 5 and 6. In this connector, in FIG. 5, the reference letter M designates a male connector housing, and F a female connector housing. The former stores first and second female terminals A and B in a plurality of terminal accommodating chambers 11 and 12 provided in the form of a matrix while the latter stores first and second male terminals A.sub.1 and B.sub.1 in terminal accommodating chambers 11 and 12 provided in the positions opposite to the above-mentioned terminal accommodating chambers 11 and 12 respectively.
The male and female connector housings M and F are fitted to each other so that the many female and male terminals A, A.sub.1 and B, B.sub.1 can be connected at the same time.
Since the male and female connector housing M and F have substantially the same configuration, only the male connector housing M will be described, by way of example, to explain the above-mentioned double locking mechanism. Locking pin insertion holes 19 and 20 are formed in a pair of side surfaces, opposite to each other, of the male connector housing M to thereby communicate with the terminal accommodating chambers 11 and 12 respectively.
A plurality of pin bodies 15 and 16 different in length (the lengths of the pin bodies are adjusted suitably in accordance with the structure of the connector housing) are provided so as to extend from one side surface of a belt-like common substrate 17 of a locking pin 18 as shown in FIG. 5. The pin bodies 15 and 16 are inserted into the holes 19 and 20 respectively.
On the other hand, as shown in the sectional view of FIG. 6 (which is a sectional view along a plane perpendicular to the direction of insertion of the locking pin and which is a sectional view illustrating a portion corresponding to the pin body 15), each female terminal A stored in the terminal accommodating chambers 11 of the male connector housing M is engaged with a locking means 13 provided integrally with a wall dividing the terminal accommodating chambers 11 from another one adjacent thereto, and a concave portion provided suitably in the terminal. The female terminal A is engaged further with the locking pin 15 inserted into the locking pin insertion hole 19 and having, for example, a rhomboidal section. Accordingly, the female terminal A is locked doubly so as not to be detached.
Accordingly, in the connector with such a double locking mechanism, female and male terminals can be accurately positioned in terminal accommodating chamber of connector housings accurately, and can be prevented from being detached. It is therefore possible to make the female and male terminals engage with each other to thereby connect electric wirings accurately to each other when the male and female connector housings are fitted to each other.
Connector housings of the connector with such a double locking mechanism are generally manufactured by injection molding of resin material. This means that variations are apt to appear in the size of terminal accommodating chambers, and so on. In addition, terminals are manufactured by pressing a metal thin plate, and are fixed by caulking end portions of electric wirings. It is therefore impossible to perfectly avoid variation in the outer size thereof.
Further, since the above-mentioned locking pin is generally manufactured by injection molding of resin material, there is a high possibility of variation in size or deformation.
If there is such a variation in size, the locking pin and the terminal do not sufficiently engage with each other when the locking pin is inserted into the locking pin insertion hole, so that there is a fear that a force to prevent the terminal from being detached is reduced, or the terminal rattles in the terminal accommodating chambers by the vibration given to the connector to thereby produce friction in the terminal or the connector housing. On the contrary, there is a case where a force to insert the locking pin into the locking pin insertion hole is so large as to problems in regard to the assembling of the connector.
In order to solve such problems, another structure is proposed in Japanese Utility Model Post-Examination Publication No. Hei-1-32299. In the structure disclosed in this publication, a flexible locking arm 60 supported on one side and covering a concave portion 70 is provided in a horizontal member 63 which is a spacer inserted into a connector housing H, so that each terminal 72 is pressed by the elastic force of the flexible locking arm 60 as shown in FIG. 7.
The above-mentioned problems such as rattling of a terminal, and so on could be solved by such a structure as shown in FIG. 7. A new problem was, however, found.
That is, as the number of terminals stored in a connector housing is increased, it is difficult to ensure that the injected resin reaches the portion corresponding to the free end of the flexible locking arm 60 at the time of molding so that the performance of molding is reduced.
In addition, when a spacer is inserted again after the spacer is once inserted and detached, there is a possibility that the flexible locking arm 60 supported on one side is caught by the terminal.